An airplane cabin is the area that contains passengers during flight. In a large commercial airplane, they generally contain rows of seats with isles so passengers can walk to and from the rest room, and the flight crew can transport needed items. In a private plane, the cabin can look more like a living room, with bench seats, tables and various specialty items along with the required belted seats and safety features. Both versions usually contain features for entertainment, like television sets and radio stations.
An airplane cabin must be pressurized in order to be comfortable for humans. Human bodies feel normal when the air pressure around them is approximately 14.7 pounds per square inch (psi), the amount felt at sea level. Commercial planes fly about 30,000 feet above sea level, where the average air pressure is about 4.3 psi. In order to raise the cabin to a comfortable level of pressure, high-pressure air is poured into the cabin area, usually recycled from the compression stage of the jet engine functions.
The cabin of a large plane is usually arranged with various classes of passengers divided by curtains. The front-most portion of the cabin is "First Class" and includes services like complimentary alcoholic beverages and extra room on all sides. Following is "Business Class" with many of the same features, but usually slightly less room on all sides. Following behind is Premium Economy with only slightly more leg room than the final division, Economy, which is sometimes called Coach. The galley and seating for the flight attendants are most often found in the back of the airplane behind Economy.
Safety is a priority in an airplane cabin. Cabins are outfitted with various materials and features to increase the passenger safety, particularly in case of an emergency. Videos are shown right before takeoff to inform and teach passengers about the safety features in the cabin, and their proper use. Generally, seats feature a flotation device in case of a water landing, and individual oxygen masks are stored in the ceiling area that drop down during an emergency. Certain areas of the cabin feature break away doors and inflatable slides for escape.
Seats are an important part of any airplane cabin, since passengers are required to sit, and be restrained during takeoff and landing, as well as when encountering turbulence or emergency situations. Comfort is certainly a factor in airplane cabin seat design, but safety is once again the greatest priority. During several high profile crashes, deaths occurred not from impact, but from seats that came loose from the cabin floor during impact. Passengers who were strapped into seats were thrown from the cabin, and perished as a result. Redesign following these crashes made seats safer, with a special flexible metal leg and attachment strip on the floor of the cabin. This allows for some spring in the seat on impact, and keeps it attached to the cabin.